1. Field of the Invention
The welding of plastic motifs, known as applique articles, to textiles using high-frequency welding machines is a process which, in itself, is not new and has been carried out for some years. However, it is not a straightforward process and there are a considerable number of problems inherent in the process which make it difficult to attain a high quality end product.
One factor, for example which determines the quality of the end product is the evenness of the weld securing the plastic motif to the fabric. In the welding process itself, it is esential that the plane of the die surface is parallel with the support for the garment to ensure an even pressure and contact of the die welding ledge on the plastics motif. The design of the welding ledge on the die is also important to ensure a good weld and a clean and easy separation of excess trim material from the plastic motif after welding. These and other factors are important to the quality of the end product.
2. Summary of the Invention
The present invention seeks to provide an improved die.
Accordingly the present invention provides a die for use in heat welding a die pattern on plastic material, the die having a first face; and at least one first elongate welding ledge upstanding on and extending along a peselected closed path on said face, said welding ledge having a first welding surface remote from and substantially parallel with said first face and a cutting edge projecting beyond said welding surface and extending along the length of the said closed path outwardly of said welding surface for severing said plastic material during welding.
Additionally, the height of the cutting edge of the first face is at least 4 mm, the width of the welding surface is at least 0.5 mm, the width of the welding ledge lies in the range of 1.5 mm to 3.0 mm, and the height of the cutting edge above the welding surface lies in the range of 0.3 mm to 0.5 mm; and a lateral surface of the cutting edge facing the adjacent first welding surface forms an angle of not more than 15.degree. to a line normal to the first welding surface.